Prior art burglar alarm systems are tedious, expensive and difficult to install. If an alarm system is desired to be installed in a completed premises, it is necessary to drill holes, break plaster walls and install a fairly complex network of wiring through the interior walls of the premises. Thus, the owner and occupants of the premises are severely inconvenienced and the time and cost for the equipment and installation is quite appreciable.
The present invention pertains to a wireless burglar alarm system wherein a receiver is positioned remotely of a wireless transmitter or transmitters and is responsive to a signal transmitted thereto by the transmitter to selectively affect the operation of a warning device connected to a receiver output.
Transmitters of the type to be employed in the wireless burglar alarm system of the present invention are described in our presently pending patent application entitled Transmitter for Producing Complex Modulated Carrier Signals, Serial No. 836,700, filed on even date herewith.
The receiver circuit assembly of the present invention is adapted to receive and demodulate a complex signal having an rf component, a mid-range audio frequency component and a low frequency component and to supply said demodulated low frequency component to output circuits associated with the receiver to selectively activate and inhibit the activation of a warning device connected to the output of one of the associated circuits as a load device.